Container for hot liquid metals

ABSTRACT

The invention relates to a container for hot liquid metals comprising a refractory lining and a bottom in which a porous, gas-permeable, refractory stone is inserted to which a conduit is joined through which a gas is blown into the liquid metal and which at least in the area below the stone is made of an easily separable material. Below the flush stone a slide is arranged through the bore of which the gas conduit is guided, and which is connected with an actuating means for closing the bore.

United States Patent 1 Hoyer [451, Dec. 24, 1974 CONTAINER FOR HOT LIQUID METALS [75] Inventor:

[73] Assignee: Vereinigte Osterreichische Eisen-und Stahlwerke Alpine lvlontan Aktiengesellschaft, Vienna [22] Filed: Aug. 20, 1973 [21] Appl. No.: 389,532

Otto Hoyer, Linz, Austria [30] Foreign Application Priority Data Aug. 21, 1972 Austria 7183/72 [52] US. Cl. 266/34 PP, 266/41 [51] Int. Cl. C21c 7/00 [58] Field of Search 266/34 A, 34 T, 34 PP,

[56] References Cited UNITED STATES PATENTS 3,581,948 6/1971 Pol Detalle 266/34 PP 3,773,226 11/1973 Kutzer ..266/34 PP Primary ExaminerGerald A. Dost Attorney, Agent, or FirmSteinberg & Blake [5 7] 7, ABSTRACT The invention relates to a container for hot liquid metals comprising a refractory lining and a bottom in which a porous, gas-permeable, refractory stone is inserted to which a conduit is joined through which a gas is blown into the liquid metal and which at least in the area below the stone is made of an easily separable material. Below the flush stone a slide is arranged through the bore of which the gas conduit is guided, and which is connected with an actuating means for closing the bore.

2 Claims, 1 Drawing Figure CONTAINER FOR HOT LIQUID METALS The invention relates to a container for hot liquid metals with a refractory lining, such as a casting ladle or tundish of a continuous casting plant or the like, in the bottom of which a porous, gas-permeable, refractory stone is inserted, to which a conduit is joined through which a gas is blown into the liquid metal.

In steel plants, in particular in high grade steel plants, for the metallurgical treatment of the liquid steel frequently ladles are used in whose bottoms a porous, gaspermeable, refractory stone is built in which is joined to a gas conduit. The gas, for example argon, which is blown through the porous stone into the liquid metal, flows through the metal and apart from separating the non-metallic particles effects also a circulation of the metal; thereby both the temperature and the concentration are equalized. These so-called flush stones have the disadvantage, however, that in the area of the porous stone or in the adjoining area the metal may easily break through which may lead to severe damages. Such steel out-breaks are a particular nuisance in ladles which are inserted in containers that can be evacuated, in which while the liquid steel is degassed flush gas is blown through the ladle bottom. Porous flush stones of the mentioned kind may also be built into tundishes of continuous casting plants in order to create a gas veil in a direction transverse to the current of the metal and thus to flush non-metallic particles, for

example alumina particles, to the surface of the metal.

Here too, severe losses may occur if the metal breaks through in the area of the flush stones and the continuous casting plant is damaged so that it must be put to a standstill.

The invention is aimed at avoiding the described disadvantages and at increasing the operational safety of such containers for hot liquid metals. It is the task of the invention to create a simple protection device by means of which damages should be avoided in case the metal breaks out. In a container of the kind defined in the introduction this task is solved according to invention by a combination of the following features:

a. the gas conduit, at least in the area below the porous stone, is made of an easily separable material, e.g., of plastic material;

b. below the porous stone a slide having a bore is arranged, preferably to be guided between two sliding plates, the gas conduit extending within said bore;

c. the slide is connected with an activating means for closing the bore, whereby under consideration of the friction resistance, the closing force is greater than the resistance of the material of the gas conduit when it is separated through.

One embodiment of the invention resides in that below the porous stone a feeler is provided which is sensitive to metal out-breaks. The feeler may comprise a wire which is electrically insulated relative to the container; the wire is connected with one pole of the supply point and a signal means may be provided which is electrically connected with the other pole of the supply point and the container, so that in case the metal breaks out an electrically conductive connection is created between the metal wire and the container as the insulation of the metal wire is destroyed and the signal means is actuated.

In order that the invention may be more fully understood an embodiment thereof shall now be explained with reference to the accompanying drawing. The drawing is a vertical sectional view of a bottom containing a built-in porous, gas-permeable, refractory stone of a metallurgical container, which bottom is provided with a means according to the invention.

In the drawing numeral 1 denotes the bottom made of refractory material of a container for liquid metal 2, e.g., of a ladle for casting steel. From below, a porous, gas-permeable refractory stone 3 together with its shell 4 surrounding its lower part can be inserted into the bottom 1. A gas conduit 5 made of plastic material is joined to the shell 4. The gas ascending in the liquid metal 2 is denoted with 6. In a hollow space 7 below the porous stone 3 an electrical wire, e.g., a wire spiral 8, is inserted, which is insulated relative to the stone 3 or to the bottom 1, respectively. The metal wire of the wire spiral 8 is connected with the one pole of a supply point 11, supplying for example alternating current of 42 Volt tension, via a conduit 9 and a fuse 10. The other pole of the supply point 11 is connected via a conduit 12 and a fuse 13 with a signal means 14, e.g., an acoustic alarm means, a blinker, or the like. The signal means 14 in its turn is electrically conductively connected with the mass, i.e., with the steel jacket 15 of the container bottom 1. When the liquid steel 2 breaks through the flush stone 3 or through the ajoining area respectively, it will be collected in the hollow space 7, and owing to the destruction of the electrical insulation of the wire spiral 8 an electrically conductive connection is provided between the wire 9 and the steel jacket 15 of the container bottom 1. In this manner, by closing the current circuit 8,9,ll,l2,15,1, the signal means 14 is actuated. In the same moment, by hand or automatically, a slide 18 provided with a bore 19, through which the gas conduit 5 and the electrical conduit 9 are guided, and which is movable between two plates 16,17

may be closed. Thereby the conduits 5,9 are separated and the slide is displaced into the position shown in dotted lines. The plates 16,17 and the slide 18 are made I of refractory material and are able to withstand the pressure and the attack of the liquid metal 2 until the melt is cast in customary manner into an outflow not shown. The slide 18 is suitably connected with a piston rod 20 of a piston 21, which may hydraulically or pneumatically be actuated, of a cylinder 22. The closing force of the cylinder 22 is such that not only the friction between the slide 18 and the plates 16,17 can be overcome but it is also sufficient to separate the plastic material conduit 5 and the metal wire 9. After the disturbance the slide 18 is opened and dismounted from the ladle bottom 15; the intruded steel is cleared from the area around the built-in flush stone 3 which is built out and may be replaced by a new stone. The slide 18 may be also closed automatically. Via the conduit 23 the conduit 12 may be connected with a relay switched in parallel or with a contractor 24 so that a switch 25 is actuated which closes a current conduit 26 which is connected with a steering aggregate not shown for actuating the cylinder 22 so that immediately when the signal means 14 is actuated the slide 18 is closed. Any customary slide can be used which is known in the art for casting liquid steel or for closing the outflow openings of ladles.

What I claim is:

l. A container for hot liquid metals comprising a refractory lining and a bottom in which a porous, gaspermeable, refractory stone is inserted to which a confeeler comprises a wire which is electrically insulated relative to the container and connected with one pole of a supply point and wherein a signal means is pro vided which is electrically connected with the other pole of the supply point and the container, so that in case the metal breaks out an electrically conductive connection is created between the metal wire and the container as the insulation of the metal wire is destroyed and the signal means is actuated. 

1. A container for hot liquid metals comprising a refractory lining and a bottom in which a porous, gas-permeable, refractory stone is inserted to which a conduit iS joined through which a gas is blown into the liquid metal, the gas conduit at least in the area below the porous stone being made of an easily separable material, and further comprising a slide with a bore below said porous stone, the gas conduit extending within said bore, and an actuating means for closing the bore which is connected with said slide, and below the porous stone a feeler which is sensitive to metal outbreaks.
 2. The container set forth in claim 1, wherein the feeler comprises a wire which is electrically insulated relative to the container and connected with one pole of a supply point and wherein a signal means is provided which is electrically connected with the other pole of the supply point and the container, so that in case the metal breaks out an electrically conductive connection is created between the metal wire and the container as the insulation of the metal wire is destroyed and the signal means is actuated. 